The objective of this study was to confirm that frequent disinfection by antiseptics is unnecessary on surgical wounds of urologic operations. Patients who received urologic operations were divided into 3 groups that had the same surgical dressings but different frequencies of disinfection and different antiseptics used. Surgical wounds were evaluated clinically and bacteriologically for the period until removal of sutures. Of the 97 patients randomly recruited for the study, 3 developed surgical-site infection (SSI). There was no significant difference in the incidence of SSI among the 3 groups. Bacterial counts of surgical wounds increased over time after operation, to similar extents in the 3 groups. The major isolate was Staphylococcus epidermidis, one of the normal florae on the skin. This strain was found at almost equal frequencies in all groups. In conclusion, our study suggested that covering with the surgical dressing without frequent disinfection by antiseptics was effective for prevention of SSI. Thus, traditional frequent disinfection should be abandoned.